Reversible regenerative furnace



p l 1933- J. B. R. BROOKE 1 2,115,613

REVERSIBLE REGENERATIVE FURNACE Filed May 17, 1937 3 Sheets-Sheet l 5nws/vme f3 1?. Beau/r5 igu A7709 V April 26, 1938.' 5 R BRQOKE 2,115,613

' REVERSIBLE REGENERATIVE FURNACE Filed May 17, 1957 5 Shets-Sheet 2Fig. 2'. 6/

mws/vroe April 1938- J. B. R. BROOKE 2,115,613

REVERS IBLE REGENERATIVE FURNACE Filed May 17, 19 57 5 Sheets-Sheet 3INVENTOR T A5. 19. Bfiaam r BY ATTUP/VEY Patented Apr. 26, 1938 UNITEDSTATES PATENT OFFICE REVERSIBLE REGENERATIVE FURNACE Application May 17,1937, Serial No. 143,173 In Great Britain October 15, 1936 9 Claims.

This invention relates to reversible regenerative furnaces having ateach side gas and air regenerator' chambers which are in communicationwith gas and air inlet passages terminating in 5 ports through which gasand air are delivered to the furnace; In an open hearth steel furnace,to which the invention is particularly applicable, it is important thata correct mixture of air and gas'should be obtained and that the flameshould be so directed that as much as possible of the heat serves toheat up the steel bath. In order 'tomaintain the direction of the flamethroughout the life of the furnace it is more important that the sizeand shape of the gas port should be' maintained than the size and shapeof the air port, because I have found that the dimensions of the airport can be considerably altered without materially affecting the shapeor direction of the flame. Now, in normal practice, the g ratio of thearea of the air port to that of the gasport lies between :1 and :1. Asit is important thatthe gas should be preheated to a temperatureapproximately equal to that of the air, it-Will be clear that thequantity of destructive waste gases that pass through the gas ports onthe way to the gas regenerator chambers must be far greater inproportion to the area of the gas ports than is the case with theairports, so that there is always a tendency for the gas ports to wearaway or to clog up, as the case may be, more quickly than the air ports.This disadvantage is particularly apparent when the furnaces are firedby coke oven and blast furnace gas, because in such a case a higherdegree of preheating of the gas is necessary and therefore more of thewaste gases must be drawn through the gas port than is the case whenproducer gas is used.

A-number of proposals have been made with the object of reducing theamount of gas passing through the gas port at the side at which the gas.

leaves the furnace. In some cases by-pass connections have been providedbetween the front of the gas port and the back of it so that some of theoutgoing gas can flow around the gas port. In otherproposals two valveshave been provided, one to shut off the gas port and the other to open aby-pass connection from the front of the gas port to the passage leadingto the gas regentJ crating chamber. The construction of such bypassconnections necessitates a departure from thenormal furnace constructionand thus is undesirable. Thus, in particular, instead of there beingmerely the gas and air ports through which so the gas and air flow in ateach side of the furnace there are also ports constituting the openings'of the by-pass connections.

The present invention aims primarily at retaining essentially thestandard port construction and yet preventing any gas from passingthrough the gas port at the side at which the gas leaves the furnace.

I provide a connection between points in the air inlet passages and thegas inlet passages respectively, together with means for opening thisconnection and simultaneously preventing the passage of gas through thegas port at the outlet side at each reversal of the furnace. It will beappreciated that with this construction there is no necessity to provideany additional ports other than those through which the air and gasenter the furnace and in fact all the gas that leaves the furnace mustleave through the air port or ports. The connection in question can takethe form of a very simple passage which can be made through thebrickwork of an existing furnace.

By employing the construction just described, a single valve member maybe employed to close the gas port at the outlet side and simultaneouslyto open the connection by which gas flowing from the furnace through theair port can pass to the gas regenerating chamber.

The connection described above may be made much larger in area than thegas port, and accordingly the area and shape of the gas port may be madethe optimum, however small or whatever shape that may be, because it isno longer necessary to enlarge it beyond the optimum in order toaccommodate a suflicient volume of waste gas.

In order that the invention may be clearly understood and readilycarried into effect two constructions in accordance therewith will nowbe described by way of example with reference to the accompanyingdrawings, in which Figure 1 is a central longitudinal section throughpart of the port structure at one side of a furnace;

Figures 2 and 3 are sections respectively on the lines II-II andIII--III of Figure 1;

Figure 4 shows the valve member on an enlarged scale;

Figure 5 is a section on the line VV of Figure 4; and

Figures 6 and '7 are sections corresponding to Figures 1 and 2 through afurnace with a modified form of valve.

Referring first to Figures 1 to 5, the furnace has the usualhearth andregenerating chambers but these are not shown. The port structurepassages respectively,

shown consists of brickwork in which there is formed a gas inlet passageI leading from the gas regenerating chamber and communicating with afurther passage 2 the end of which constitutes the gas port 3. Two airinlet passages 4 and lead from the air regenerator chamber to a passageor space '6 in which the air that rises up them unites, flowing throughthis passage, the end of which constitutes the air port 1 which isarranged to deliver air around the gas delivered by the gas port 3. Theports and passages so far described are all of standard construction.

According to the invention a connection 8 is formed in the brickwork atthe top of the furnace between the space or passage 6 and the gaspassage I. This connection is controlled by a water-cooled damper 9which slides in a watercooled chase II] which extends through thebrickwork across the connection 8 and also across the gas passage 2. Thedamper 9 is ported, being formed with an opening I l. Figures 4 and 5show the construction of the damper in detail and in particular the wayin which water-cooling tubes [2 are arranged within it.

A single-acting hydraulic motor i3 is connected through a rope l4passing over pulleys 5 to the top of the damper 9 and when this motor isoperated it raises the damper against the influence of gravity.

When gas and air are entering at the side of the furnace illustrated thedamper is raised and closes the connection 8 and opens the gas passage2. When the gas is leaving the furnace at the side illustrated thedamper is lowered into the position shown in Figure l, and it will beseen that the opening ll then registers with the connection 8 and thatthe gas passage is closed so that no gas flows through the port 3. Allthe gas leaving the furnace passes through the air port I and it dividesat the point where the air passages 4 and 5 meet, some passing througheach of these passages and some through the connection 8 and down thegas passage I. It will be understood that the amounts of the waste gasthat pass through the air and gas regenerator chambers respectively maybe varied in any appropriate way, such as by varying the suctionapplied.

The two operating motors l3 of the furnace are preferably synchronizedwith the main gas reversing valve so that the valve members areautomatically moved whenever the furnace is reversed.

In the modified construction shown in Figures 6 and 7 the onlydifference is that the sliding damper is replaced by a pivoted damper itcarried by a spindle I! through which water is introduced to cool thedamper. A water-cooled frame it is provided to constitute an abutmentfor the damper l6 in its two operating positions.

A particular advantage of the construction according to the invention isthat the gas port need not be water-cooled and that water-cooling can beconfined to a part of the furnace which is readily accessible by the rmoval of a minimum of brickwork.

I claim:-

1. In a reversible regenerative furnace, a port structure formed withgas and air inlet passages terminating in ports and, with a connectionrunning between points in said gas and air inlet a single valve memberwhich in one position opens said connection to place the gas and airinlet passages in communication with one another and simultaneouslycloses the gas port, and in the other position closes said connection toshut off the gas and air inlet passage from one another andsimultaneously opens the gas port to place it in com munication with thegas inlet passage.

2. In a reversible regenerative furnace, a port structure formed withgas and air inlet passages terminating in ports in a fixed part of thestructure and with a connection running between points in said gas andair inlet passages respectively, and a single valve member which in oneposition opens said connection to place the gas and air inlet passagesin communication with one another and simultaneously closes the gasport, and in the other position closes said connection to shut off thegas and air inlet passage from one another and simultaneously opens thegas port to place it in communication with the gas inlet passage.

3. In a reversible regenerative furnace, a port structure at each sideof the furnace, each of said port structures being formed with a gasinlet passage terminating in a gas port and with two inlet passagesmeeting together and terminating in an air port arranged to deliver airadjacent gas leaving the gas port and also with a connection runningfrom the point where said air inlet passages meet, and a single valvemember which in one position opens said connection to place the gas andair inlet passages in communication with one another and simultaneouslycloses the gas port, and in the other position closes said connection toshut off the gas and air inlet passage from one another andsimultaneously opens the gas port to place it in communication with thegas inlet passage.

4. In a reversible regenerative furnace, a port structure formed withgas and air inlet passages terminating in ports and with a connectionrunning between points in said gas and air inlet passages respectively,and a single valve member in the form of a ported slide valve which inone position opens said connection to place the gas and air inletpassages in communication with one another and simultaneously closes thegas port, and in the other position closes said connection to shut offthe gas and air inlet passage from one another and simultaneously opensthe gas port to place it in communication with the gas inlet passage.

5. In a reversible regenerative furnace, a port structure formed withgas and air inlet passages terminating in ports in a fixed part of thestructure and with a connection running between points in said gas andair inlet passages respectively, and a single valve member in the formof a ported slide valve which in one position opens said connection toplace the gas and air inlet passages in communication with one anotherand simultaneously closes the gas port, and in the other position closessaid connection to shut oiT the gas and air inlet passage from oneanother and simultaneously opens the gas port to place it incommunication with the gas inlet passage.

6. In a reversible regenerative furnace, a port structure at each sideof the furnace, each of said port structures being formed with a gasinlet passage terminating in a gas port and with two air inlet passagesmeeting together and terminating in an air port arranged to deliver airadjacent gas leaving the gas port and also with a connection runningfrom the point where said air inlet passages meet, and a single valvemember in the form of a ported slide valve which in one position openssaid connection to place the gas and air inlet passages in communicationwith one another and simultaneously closes the gas port, and in theother position closes said connection to shut off the gas and air inletpassage from one another and simultaneously opens the gas port to placeit in communication with the gas inlet passage.

7. In a reversible regenerative furnace, a port structure formed withgas and air inlet passages terminating in ports and with a connectionrunning between points in said gas and air inlet passages respectively,and a single valve member in the form of a pivoted damper which in oneposition opens said connection to place the gas and air inlet passagesin communication with one another and in another position closes saidconnection to shut off the gas and air inlet passage from one anotherand simultaneously opens connection to place the gas and air inletpassages in communication with one another and simultaneously closes thegas port, and in the other position closes said connection to shut oilthe gas and air inlet passage from one another and simultaneously opensthe gas port to place it in communication with the gas inlet passage.

9. In a reversible regenerative furnace, a port structure at each sideof the furnace, each of said port structures being formed with a gasinlet passage terminating in a gas port and with two air inlet passagesmeeting together and terminating in an air port arranged to deliver airadjacent gas leaving the gas port and also with a connection runningfrom the point where said air inlet passages meet, and a single valvemember in the form of a pivoted damper which in one position opens saidconnection to place the gas and air inlet passages in communication withone another and simultaneously closes the gas port, and in the otherposition closes said connection to shut oil? the gas and air inletpassage from one another and simultaneously opens the gas port to placeit in communication with the gas inlet passage.

JOSEPH BLAKE ROW'LEY BROOKE.

